The MoD said work on the five new vessels is sustaining 800 jobs at shipyards on the Clyde through contracted work and by guaranteeing the “crucial manufacturing skills” needed to build the Navy’s future Type 26 Frigates.

Mrs Baldwin said: “This contract will deliver two more modern offshore patrol vessels, HMS Tamar and HMS Spey, for the Royal Navy and safeguard vital shipbuilding skills and hundreds of jobs in Scotland.

“Protected by a rising fefence budget, the OPV programme is an important part of the Government’s £178 billion plan to ensure our armed forces have the equipment they need.”

Like the other vessels of their class, HMS Tamar and HMS Spey will carry out counter-terrorism, anti-piracy, anti-smuggling and maritime defence operations, and are expected to be equipped with a 30mm cannon and a flight deck capable of receiving a Merlin helicopter.

Displacing around 2,000 tonnes, they will have a maximum speed of 24 knots and will be able to sail 5,500 nautical miles before having to resupply.

The MOD said that as well as sustaining around 800 Scottish shipbuilding jobs on the Clyde, the OPV programme sustains additional jobs at more than 100 companies in the UK supply chain.

Tony Douglas, chief executive officer at the MoD’s defence equipment and support organisation, said: “This agreement will deliver two more offshore patrol vessels which the Royal Navy will use to protect the nation’s interest at home and around the world.

“These modern ships will have a versatile flight deck, improved firefighting equipment and greater storage and accommodation than previous vessels, giving UK sailors a decisive advantage on a huge range of operations.”

BAE Systems is currently exploring a number of export opportunities with international customers for OPV.

The Brazilian Navy operates three Amazonas Class corvettes which are based on the design of the river-class OPV and were built at BAE Systems’ facilities in the UK.